高幅值地震动参数及其潜在破坏势

Parameters and damage potential of large-amplitude ground motions

为研究高幅值地震动特性与影响,并针对该类地震动改进设计谱,统计了20次地震中60条满足PGA≥1 g、PGV≥100 cm/s、PGD≥100 cm三个条件之一的地震动记录,并计算相关参数.首先综合之前提出的与地震动特性相关的破坏势评价标准,采用因子分析法对各评价标准进行降维,得到新的综合因子,实现原始变量整合与简化,并对综合因子的物理意义给出解释.同时计算了高幅值地震动记录的特征周期和最大规准谱谱值,比较与现有规范给定值的差异,针对该类特殊地震动发生的可能性,为设计谱的完善提出建议.

To study the properties and effects of high-amplitude ground motion, while modifying the design spectra, 60 records from 20 events satisfying at least one of the following requirements： PGA ≥ 1 g, PGV ≥ 100 cm/s or PGD ≥100 cm, were collected and analyzed. The evaluation factors for ground motions＇ damage potential related with the ground motions＇ characteristics were summarized and the Factor Analysis Method was used to realize the simplification and integration. Explanation of new factors＇ physical meanings was also discussed. Additionally, characteristic periods and the maximum amplification coefficients for the large-amplitude ground motions were calculated and compared with those adopted in current design codes. Suggestions on the modification of design spectra were indicated based on the possibility of potential hazard.